Which one of the following is a complete and accurate list of those planes any one of which could be within area T at...

Karen-Norris December 2, 2021

I have a similar question. During the set-up it's explained that since J is in S, K cannot be in S, and also because T intersects with S, K likewise cannot be in T, and because U falls within the intersection of R and T, that K, likewise cannot be in U. So, for the K variable, we are treating the areas of S, T, and U, as if the whole of area T is contaminated by the overlap of part of S, and that the whole of area U, is also contaminated by the overlap of T, which is contaminated by S. HOWEVER, for determining the placement of M. We are acting like only the overlapping areas of the circle are contaminated, and that the areas not so enveloped are single areas. I hope my question as posed makes sense.

Ravi February 12, 2022

It's true that part of T intersects R, but that overlap is not 100%. Therefore, there are areas of R not in T and areas of T not in R, so it's possible for K to be in R while J is in T, as long as they're not in the overlapping parts.

Karen, that's correct. The overlapping areas are the ones that are problematic here, whereas the areas without overlap are totally fine.